The invention relates to a rotor in BLISK or BLING design of an aircraft engine.
It is a known problem that the fan blades of an aircraft engine may be stimulated to vibrate due to a variety of different flow conditions. At that, the chance of undesired vibrations of the fan blades occurring is especially high when the fan is manufactured in an integral BLISK design (BLISK=“blade integrated disc”), i.e. as a structural component that is formed in one piece and comprises the fan blades as well as the fan disc, or that is realized in an integral BLING design (BLING=“bladed ring”), i.e. with the blades being manufactured integrally with the supporting ring. This has to do with the fact that fans manufactured in an integral design do no longer have separate blade-disc connections which contribute to the mechanical damping of the system.
Due to the lower degree of mechanical damping of integral blade-disc constructions, the maximal vibration amplitude of the fan blades is caused almost exclusively by the aerodynamic edge conditions. This may lead to strong stress and deformation in particular in operational states with a low or even negative aerodynamic damping (flutter), which has a strongly negative effect on the service life of the fan, or may even cause incipient cracks.
The problems that have been explained in connection with fans occur in rotors in BLISK or BLING design in general.
There is a need to provide measures by means of which the damping characteristics of a rotor in BLISK or BLING design, in particular of a fan in BLISK or BLING design, are improved, so that the rotor is less prone to be stimulated to vibrate.